A (meth)acrylate compound is copolymerized with any other polymerizable monomer, and is used in various applications, such as an optical material, a resist material, a coating material and a laminate material. The resist material is widely used in a process in which patterning is conducted by photolithography to perform microprocessing, or the like, such as manufacture of a printed circuit board, a liquid crystal display panel and a semiconductor device. In particular, in the process of photolithography for manufacturing the semiconductor device, study has been conducted on short wavelength exposure for shortening an exposure wavelength to increase resolution in order to allow further microprocessing, and study has been actively conducted on a chemical amplification type resist material in correspondence to the short wavelength exposure.
The chemical amplification type resist material is mainly provided as a structure formed by combining a polymer component obtained by copolymerizing a plurality of polymerizable monomers such as a (meth)acrylate compound, a photoacid generator that is exposed to an exposure light source to change solubility of the polymer component, a solvent and so forth. The resist material is required to satisfy characteristics such as application properties, adhesion, treatment resistance, developability and solubility, and also to satisfy characteristics related to an exposure wavelength, such as light transmittance and light sensitivity.
The polymer component is required to have high transmittance at the exposure wavelength, to cause a deprotection reaction in an exposed portion by acid generated from the photoacid generator after exposure to solubilize or conversely insolubilize the portion in an alkali liquid developer, to have good adhesion and etching-resistant properties of a resist, and simultaneously to satisfy lithography characteristics such as reduction of roughness of the resulting resist pattern and fluctuation of pattern width, and resistance to a pattern collapse in association with a demand for achieving a fine resist pattern. In order to balance the characteristics, the polymer component obtained by copolymerizing a plurality of polymerizable monomers is used.
For example, polymer components are combined and used in which the polymer components are obtained by copolymerizing a polymerizable monomer such as a lactone-based (meth)acrylate compound in which the light transmittance is high at the exposure wavelength and the adhesion properties is good, a polymerizable monomer having an adamantane skeleton, a norbornane skeleton or alicyclic skeleton in which the light transmittance is high at the exposure wavelength and etching resistance is good, a polymerizable monomer that is decomposed by the acid generator to be alkali-soluble, an alkali-soluble polymerizable monomer and so forth.
Study has been actively conducted toward realization of a chemical amplification type resist material having well-balanced characteristics by developing various kinds of polymerizable compounds such as a compound having a 6-membered ring lactone (δ-valerolactone) skeleton as the lactone-based (meth)acrylate compound, a compound having a 5-membered ring lactone (γ-butyrolactone) skeleton, a compound having a skeleton in which norbornane and lactone form a condensed ring, and a compound having cyclohexane lactone ring structure, and incorporating the compounds as the polymer components.
As the (meth)acrylate compound having the 5-membered ring lactone (γ-butyrolactone) skeleton, α-(meth)acryloyloxy-γ-butyrolactones (Patent literature No. 1) and β-(meth)acryloyloxy-γ-butyrolactones (Patent literature No. 2) are known. In particular, α-(meth)acryloyloxy-γ-butyrolactones that have a substituent at an α-position are industrially provided, and usefully used for a chemical amplification-type resist composition. On the other hand, β-(meth)acryloyloxy-γ-butyrolactones are difficult to industrially manufacture, industrial use of which is limited, and no synthesis has been made until now depending on structure of the compound.
The β-(meth)acryloyloxy-γ-butyrolactones are known to be further excellent in deprotection reaction characteristics by acid and lithography characteristics in comparison with the α-(meth)acryloyloxy-γ-butyrolactones, and establishment of a method by which the β-(meth)acryloyloxy-γ-butyrolactones can be industrially and inexpensively manufactured is required (Non-patent literature No. 1).
With regard to the β-(meth)acryloyloxy-γ-butyrolactones and a method for manufacturing the same, a method is known in which β-hydroxy-γ-butyrolactones are obtained to be esterified with (meth)acrylic acid chloride or (meth)acrylic acid, or transesterified with (meth)acrylate (Patent literature No. 2), and a method is also known in which (meth)acrylic acid is allowed to react with halo-γ-butyrolactones (Patent literature No. 3). All of the manufacturing methods include a method for manufacturing a compound having a hydroxy group or a halogen group at a β-position of a γ-butyrolactone ring to manufacture the compound by an esterification reaction with (meth)acrylic acid or a derivative thereof.
As a method for manufacturing the compound having the hydroxy group at the β-position of the γ-butyrolactone ring, such methods are known as a method for esterifying halide bromoacetate with hydroxyacetone or 3-hydroxypropionaldehyde to prepare 2-oxopropyl bromoacetate or 2-formylethyl bromoacetate, and to lactonize the resulting product in the presence of a catalyst and to obtain β-hydroxy-β-methyl-γ-butyrolactone or β-hydroxy-γ-butyrolactone (Patent literature No. 2), a method for manufacturing the compound from 3,4-dihydroxybutyric acid (Patent literature Nos. 4 and 7), and a method for manufacturing the compound using (β,γ-unsaturated carboxylic acid as a raw material. (Patent literature No. 5).
In the method for obtaining β-hydroxy-β-methyl-γ-butyrolactone or β-hydroxy-γ-butyrolactone through 2-oxopropyl bromoacetate or 2-formylethyl bromoacetate from esterification of halide bromoacetate, and hydroxyacetone or 3-hydroxypropionaldehyde, a yield in each step is low, pretreatment of zinc powder to be used as a catalyst is required, or the like, and thus the method is difficult to utilize as an industrial manufacturing method.
In the method for manufacturing the compound from 3,4-dihydroxybutyric acid, hydrogen peroxide is used (Patent literature No. 4) or cyanide is used (Patent literature No. 7) in order to manufacture 3,4-dihydroxybutyric acid. Therefore, according to a technique, a substance having a risk of explosion or toxicity should be used.
The method for manufacturing the compound using β,γ-unsaturated carboxylic acid as the raw material is excellent in synthesizing β-hydroxy-γ-butyrolactone in one step by using 3-butenoic acid as the raw material. However, the method also includes a reaction using hydrogen peroxide, and requires suitable process control and waste disposal.
Thus, according to the methods in which the compound having the hydroxy group at the β-position of γ-butyrolactones is previously formed to manufacture the compound by the esterification reaction with (meth)acrylic acid or the derivative thereof as a hydroxy form or a halogen form thereof, a yield in manufacturing a β-hydroxy form compound or a β-halogen form compound of γ-butyrolactones is low, manufacturing conditions are tough, synthesis of a starting material is required due to incapability of industrially utilizing the material and so forth, and therefore the compound is difficult to manufacture in bulk and inexpensively. As a result, the β-(meth)acryloyloxy-γ-butyrolactones have had a problem of incapability of industrially manufacturing the compound inexpensively.
As the method for forming the γ-butyrolactone skeleton, a compound having a β-propiolactone skeleton is known to be isomerized to form the γ-butyrolactone skeleton (Non-patent literature No. 2). In the case where a hydroxy form compound of γ-butyrolactones is manufactured by applying the above method, manufacture of a hydroxymethyl form compound having the β-propiolactone skeleton corresponding to the hydroxy form compound of γ-butyrolactones is previously required.
As the method for manufacturing the compound having the β-propiolactone skeleton, a method for allowing aliphatic aldehydes to react with ketenes is known (Patent literature No. 6), for example, and application of the method to synthesis of low-molecular-weight lactone having a β-skeleton, such as β-butyrolactone, β-propiolactone and β-caprolactone is disclosed.
However, manufacture of the hydroxy form compound having the β-propiolactone skeleton by applying the method is difficult to industrially execute due to difficulty in manufacture of the compound to be the raw material to cause difficulty in procurement, many side reactions to cause poor reaction selectivity, or the like. Accordingly, industrial manufacture of the β-hydroxy form compound of γ-butyrolactones is still difficult, and as a result, establishment of a new method for industrially manufacturing the β-(meth)acryloyloxy-γ-butyrolactones has been strongly required.